CAS Key Laboratory of Crust-Mantle Materials and Environment, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, Anhui, 230026, China; State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, The Chinese Academy of Sciences, Xi'an, Shaanxi, 710075, China.
CAS Key Laboratory of Crust-Mantle Materials and Environment, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, Anhui, 230026, China; Department of Environmental Engineering, Middle East Technical University, 06800, Ankara, Turkey.
Ecotoxicol Environ Saf. 2020 Mar 15;191:110244. doi: 10.1016/j.ecoenv.2020.110244. Epub 2020 Jan 28.
The purpose of this research was to examine the influence of hydrothermally treated coal gangue (HTCG) with and without biochar (BC) on the leaching, bioavailability, and redistribution of chemical fractions of heavy metals (HMs) in copper mine tailing (Cu-MT). An increase in pH, water holding capacity (WHC) and soil organic carbon (SOC) were observed due to the addition of BC in combination with raw coal gangue (RCG) and HTCG. A high Cu and other HMs concentration in pore water (PW) and amended Cu-MT were reduced by the combination of BC with RCG and/or HTCG, whereas individual application of RCG slightly increased the Cu, Cd, and Zn leaching and bioavailability, compared to the unamended Cu-MT. Sequential extractions results showed a reduction in the exchangeable fraction of Cu, Cd, Pb, and Zn and elevation in the residual fraction following the addition of BC-2% and BC-HTCG. However, individual application of RCG slightly increased the Cu, Cd, and Zn exchangeable fractions assessed by chemical extraction method. Rapeseed was grown for the following 45 days during which physiological parameters, metal uptake transfer rate (TR), bioconcentration factor (BCF), and translocation factor (TF) were measured after harvesting. In the case of plant biomass, no significant difference between applied amendments was observed for the fresh biomass (FBM) and dry biomass (DBM) of shoots and roots of rapeseed. However, BC-2% and BC-HTCG presented the lowest HMs uptake, TR, BCF (BCF and BCF), and TF for Cu, Cd, Cr, Ni, Pb, and Zn in rapeseed among the other amendments compared to the unamended Cu-MT. Overall, these findings are indicative that using biochar in combination with RCG and/or HTCG led to a larger reduction in HMs leaching and bioavailability, due to their higher sorption capacity and could be a suitable remediation strategy for heavy metals in a Cu-MT.
本研究旨在考察经水热处理的煤矸石（HTCG）和添加生物炭（BC）的煤矸石对铜矿尾矿（Cu-MT）中重金属（HM）浸出、生物可利用性和化学形态再分配的影响。由于添加了 BC，RCG 和 HTCG 的 pH 值、持水能力（WHC）和土壤有机碳（SOC）都有所增加。与未添加 BC 的 Cu-MT 相比，BC 与 RCG 和/或 HTCG 的结合降低了 Cu 和其他 HM 在孔隙水中（PW）和改良 Cu-MT 中的浓度，但与未添加 Cu-MT 相比，RCG 的单独应用略微增加了 Cu、Cd 和 Zn 的浸出和生物可利用性。顺序提取结果表明，添加 BC-2%和 BC-HTCG 后，Cu、Cd、Pb 和 Zn 的可交换分数减少，残渣分数增加。然而，与未添加 Cu-MT 相比，RCG 的单独应用略微增加了化学提取法评估的 Cu、Cd 和 Zn 的可交换分数。在接下来的 45 天里，种植了油菜，在收获后测量了油菜的生理参数、金属吸收转移率（TR）、生物浓缩因子（BCF）和转移因子（TF）。在植物生物量方面，与其他添加物相比，添加物对油菜地上和地下部分的鲜重（FBM）和干重（DBM）没有显著差异。然而，BC-2%和 BC-HTCG 在油菜中对 Cu、Cd、Cr、Ni、Pb 和 Zn 的吸收、TR、BCF（BCF 和 BCF）和 TF 最低，与未添加 Cu-MT 的相比，这表明使用生物炭与 RCG 和/或 HTCG 结合使用，由于其具有更高的吸附能力，导致 HMs 的浸出和生物可利用性更大程度降低，这可能是一种在 Cu-MT 中修复重金属的合适策略。
